JP7436766B2 - Intake manifold and engine - Google Patents

Description

The present invention relates to intake manifolds and engines.

Patent Document 1 discloses an engine accessory support structure in which a fuel supply device as an example of an engine accessory is attached to an engine body. The fuel supply device described in Patent Document 1 includes a throttle and a gas mixer. In the engine accessory support structure described in Patent Document 1, a mixture of fuel and air mixed with each other by a gas mixer passes through a throttle and is guided to an intake body of an intake manifold.

Here, the flow direction of the air-fuel mixture when it passes through the throttle is parallel to the flow direction of the air-fuel mixture when it flows through the intake body. That is, the air-fuel mixture supplied from the gas mixer passes through the throttle and flows through the intake body along the axis of the gas mixer without changing the flow direction. The air-fuel mixture that has flowed through the intake main body is then distributed to a plurality of cylinders of the engine by a plurality of intake pipes of an intake manifold.

Therefore, the engine auxiliary equipment support structure described in Patent Document 1 has room for improvement in terms of improving the degree of mixing of fuel and air and suppressing variations in air-fuel ratio among multiple cylinders of the engine.

JP 2017-78352 Publication

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an intake manifold and an engine that can suppress variations in air-fuel ratio among a plurality of cylinders.

The problem is an intake manifold that guides a mixture containing fuel and air to a plurality of cylinders of an engine. a plurality of intake pipes that distribute the air-fuel mixture to the plurality of cylinders, the intake main body receiving the air-fuel mixture that has passed through the throttle, and a a flow direction changing section that changes the flow direction of the air-fuel mixture from one flow direction to a second flow direction different from the first flow direction; The problem is solved by an intake manifold according to the present invention, characterized in that the intake manifold has a collecting part that guides the intake pipes along the pipes and then leads to the plurality of intake pipes.

The intake manifold according to the present invention includes an intake main body and a plurality of intake pipes, and the air-fuel mixture containing fuel and air, which is led from the intake main body, is passed through the plurality of intake pipes to the plurality of intake pipes. Distribute to cylinders. The intake main body has a flow direction changing part and a gathering part. The flow direction changing unit receives the air-fuel mixture that has passed through the throttle, and changes the flow direction of the air-fuel mixture from the first flow direction to the second flow direction. The first flow direction is the flow direction when the air-fuel mixture passes through the throttle. The second flow direction is a flow direction different from the first flow direction. The collecting section guides the air-fuel mixture guided from the flow direction changing section along the second flow direction, and then guides it to the plurality of intake pipes.

In this way, the air-fuel mixture that has passed through the throttle has its flow direction changed from the first flow direction to the second flow direction in the flow direction changing section, and is then moved along the changed flow direction (i.e., the second flow direction). Flowing through the gathering area. Therefore, the degree of mixing of fuel and air in the air-fuel mixture that has passed through the throttle is improved in the flow direction changing section. Then, the air-fuel mixture with an improved mixing degree flows through the gathering portion along the second flow direction, and then is guided to the plurality of intake pipes. This makes it possible to suppress variations in air-fuel ratio between multiple cylinders of the engine.

Further, since it is possible to improve the degree of mixing of the air-fuel mixture and to suppress variations in air-fuel ratio among a plurality of cylinders of the engine, it is possible to reduce the volume of the gathering portion. That is, even without ensuring a relatively large volume of the collecting section, it is possible to improve the mixing degree of the air-fuel mixture in the flow direction changing section and to suppress variations in the air-fuel ratio among the plurality of cylinders of the engine. Thereby, the intake manifold can be made smaller.

In the intake manifold according to the present invention, preferably, the second flow direction is perpendicular to the first flow direction.

According to the intake manifold according to the present invention, the flow direction of the air-fuel mixture that has passed through the throttle is changed from the first flow direction to the second flow direction perpendicular to the first flow direction in the flow direction changing section. Thereby, the degree of mixing of fuel and air in the air-fuel mixture that has passed through the throttle is further improved at the flow direction changing portion.

In the intake manifold according to the present invention, preferably, the fuel is a gaseous fuel, and the mixture passing through the throttle is a mixture of the gaseous fuel and the air mixed with each other by a gas mixer. Features.

According to the intake manifold according to the present invention, the fuel is gaseous fuel. Therefore, the intake manifold according to the present invention guides a mixture containing gaseous fuel and air to a plurality of cylinders of an engine. In other words, the engine to which the intake manifold according to the present invention is attached is a gas engine. The air-fuel mixture passing through the throttle is a mixture of gaseous fuel and air mixed with each other by a gas mixer. Therefore, the air-fuel mixture supplied from the gas mixer passes through the throttle, changes the flow direction from the first flow direction to the second flow direction in the flow direction changing section, and then changes the flow direction (i.e., the second flow direction). ) flows through the collection point. Therefore, the degree of mixing of gaseous fuel and air in the air-fuel mixture that has passed through the throttle is improved in the flow direction changing section. Then, the air-fuel mixture with an improved mixing degree flows through the gathering portion along the second flow direction, and then is guided to the plurality of intake pipes. This makes it possible to suppress variations in the air-fuel ratio between the plurality of cylinders of the engine, in other words, variations in the concentration of gaseous fuel between the plurality of cylinders of the engine.

The above object includes a throttle, an intake manifold that guides a mixture containing fuel and air that has passed through the throttle, and a plurality of cylinders that take inside the mixture supplied from the intake manifold, The manifold includes an intake body that guides the mixture that has passed through the throttle, and a plurality of intake pipes that are connected to the intake body and distribute the mixture led from the intake body to the plurality of cylinders. , the intake body receives the air-fuel mixture that has passed through the throttle, and directs the air-fuel mixture from a first flow direction when the air-fuel mixture passes through the throttle to a second flow direction different from the first flow direction. A flow direction changing part that changes the flow direction; and a collecting part that guides the mixture guided from the flow direction changing part along the second flow direction and then to the plurality of intake pipes. This problem is solved by an engine according to the present invention.

An engine according to the present invention includes a throttle, an intake manifold, and a plurality of cylinders. The intake manifold includes an intake body and a plurality of intake pipes, and distributes the mixture containing fuel and air, which is led from the intake body, to a plurality of cylinders of the engine through the plurality of intake pipes. . The intake main body has a flow direction changing part and a gathering part. The flow direction changing unit receives the air-fuel mixture that has passed through the throttle, and changes the flow direction of the air-fuel mixture from the first flow direction to the second flow direction. The first flow direction is the flow direction when the air-fuel mixture passes through the throttle. The second flow direction is a flow direction different from the first flow direction. The collecting section guides the air-fuel mixture guided from the flow direction changing section along the second flow direction, and then guides it to the plurality of intake pipes.

In this way, the air-fuel mixture that has passed through the throttle has its flow direction changed from the first flow direction to the second flow direction in the flow direction changing section, and is then moved along the changed flow direction (i.e., the second flow direction). Flowing through the gathering area. Therefore, the degree of mixing of fuel and air in the air-fuel mixture that has passed through the throttle is improved in the flow direction changing section. Then, the air-fuel mixture with an improved mixing degree flows through the gathering portion along the second flow direction, and then is guided to the plurality of intake pipes. This makes it possible to suppress variations in air-fuel ratio between multiple cylinders of the engine.

Further, since it is possible to improve the degree of mixing of the air-fuel mixture and to suppress variations in air-fuel ratio among a plurality of cylinders of the engine, it is possible to reduce the volume of the gathering portion. That is, even without ensuring a relatively large volume of the collecting section, it is possible to improve the mixing degree of the air-fuel mixture in the flow direction changing section and to suppress variations in the air-fuel ratio among the plurality of cylinders of the engine. Thereby, the intake manifold can be made smaller.

In the engine according to the present invention, preferably the fuel is gaseous fuel. The engine according to the present invention is characterized in that the engine further includes a gas mixer that mixes the gaseous fuel and the air to generate the air-fuel mixture and supplies the air-fuel mixture to the throttle.

According to the engine according to the present invention, the fuel is gaseous fuel. That is, the engine according to the present invention is a gas engine. The air-fuel mixture passing through the throttle is a mixture of gaseous fuel and air mixed with each other by a gas mixer. Therefore, the air-fuel mixture supplied from the gas mixer passes through the throttle, changes the flow direction from the first flow direction to the second flow direction in the flow direction changing section, and then changes the flow direction (i.e., the second flow direction). ) flows through the collection point. Therefore, the degree of mixing of gaseous fuel and air in the air-fuel mixture that has passed through the throttle is improved in the flow direction changing section. Then, the air-fuel mixture with an improved mixing degree flows through the gathering portion along the second flow direction, and then is guided to the plurality of intake pipes. This makes it possible to suppress variations in the air-fuel ratio between the plurality of cylinders of the engine, in other words, variations in the concentration of gaseous fuel between the plurality of cylinders of the engine.

According to the present invention, it is possible to provide an intake manifold and an engine that can suppress variations in air-fuel ratio between a plurality of cylinders.

1 is a perspective view showing an engine according to an embodiment of the present invention. FIG. 2 is a sectional view taken along the cutting plane AA shown in FIG. 1. FIG. FIG. 3 is a cross-sectional view showing a peripheral structure of an intake manifold of an engine according to a comparative example. 3 is a graph illustrating the relationship between each intake port and equivalence ratio of the engine according to the present embodiment. It is a graph which illustrates the relationship between each intake port of the engine concerning a comparative example, and equivalence ratio.

Below, preferred embodiments of the present invention will be described in detail with reference to the drawings.
The embodiments described below are preferred specific examples of the present invention, and therefore have various technically preferable limitations. However, the scope of the present invention does not particularly limit the present invention in the following description. Unless otherwise specified, the embodiments are not limited to these embodiments. Further, in each drawing, similar components are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a perspective view showing an engine according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the cutting plane AA shown in FIG.
FIG. 3 is a sectional view showing a peripheral structure of an intake manifold of an engine according to a comparative example.

The engine 2 according to the present embodiment is, for example, an internal combustion engine that operates on gaseous fuel such as natural gas, LPG, or biogas, that is, a gas engine. Note that the engine 2 according to this embodiment may be used not only as a gas engine but also as an industrial diesel engine. The engine 2 shown in FIG. 1 is a four-cylinder engine, and is installed in, for example, vehicles such as construction machinery, agricultural machinery, and lawn mowers.

As shown in FIG. 1, the engine 2 includes a cylinder block 3, a cylinder head 4, a head cover 5, an oil pan 6, and an intake manifold 8. The cylinder block 3 has a crankcase 31 formed at the bottom and a cylinder (not shown) formed at the top. As mentioned above, the engine 2 shown in FIG. 1 has four cylinders. The cylinder head 4 is assembled to the upper part of the cylinder block 3. The head cover 5 is attached to the upper part of the cylinder head 4. The oil pan 6 is assembled to the lower part of the cylinder block 3 (specifically, the lower part of the crankcase 31).

The intake manifold 8 is assembled to a side portion of the cylinder head 4 and includes an intake main body 81 and a plurality of intake pipes 82. The plurality of intake pipes 82 include a first intake pipe 821 , a second intake pipe 822 , a third intake pipe 823 , and a fourth intake pipe 824 . That is, the intake manifold 8 according to the present embodiment includes a first intake pipe 821 , a second intake pipe 822 , a third intake pipe 823 , and a fourth intake pipe 824 as the plurality of intake pipes 82 .

The first intake pipe 821 is connected to a first cylinder (not shown) formed in the cylinder block 3 via a first intake port (not shown) formed in the cylinder head 4 . The second intake pipe 822 is connected to a second cylinder (not shown) formed in the cylinder block 3 via a second intake port (not shown) formed in the cylinder head 4 . The third intake pipe 823 is connected to a third cylinder (not shown) formed in the cylinder block 3 via a third intake port (not shown) formed in the cylinder head 4 . The fourth intake pipe 824 is connected to a fourth cylinder (not shown) formed in the cylinder block 3 via a fourth intake port (not shown) formed in the cylinder head 4 .

Further, as shown in FIG. 1, the engine 2 includes a gas mixer 91 and a throttle 92 (for example, an electronically controlled throttle) that function as at least part of a fuel supply device. When the engine 2 is used as an industrial diesel engine, the gas mixer 91 is not necessarily a necessary component. Gaseous fuel such as natural gas, LPG, and biogas is supplied to the gas mixer 91 as indicated by an arrow A1 shown in FIG. Further, air sucked through the air cleaner is supplied to the gas mixer 91, as indicated by arrow A2 in FIG. The gas mixer 91 mixes fuel and air with each other at an appropriate ratio so that the gaseous fuel is easily combusted, and supplies a mixture containing fuel and air to the cylinders of the engine 2 through the throttle 92 and the intake manifold 8. The ratio of fuel and air mixed by the gas mixer 91, that is, the ratio of fuel and air contained in the air-fuel mixture, is called an air-fuel ratio or an air-fuel ratio.

The intake manifold 8 according to this embodiment guides a mixture containing fuel and air to a plurality of cylinders of the engine 2. Specifically, as shown in FIG. 2, the intake main body 81 is connected to a gas mixer 91 via a throttle 92, and guides the air-fuel mixture that has passed through the throttle 92 to the plurality of intake pipes 82. As shown in FIG. 2, the intake main body 81 includes a flow direction changing section 811 and a gathering section 812. The flow direction changing section 811 is arranged upstream of the flow of the air-fuel mixture from the gathering section 812, and is connected to the gas mixer 91 via the throttle 92 at the upstream section, and connected to the gathering section 812 at the downstream section. . The collecting portion 812 is arranged downstream of the flow direction changing portion 811 in the flow of the air-fuel mixture, and is connected to the flow direction changing portion 811 at the upstream portion and to the plurality of intake pipes 82 at the downstream portion. .

As indicated by an arrow A11 shown in FIG. 2, a mixture of fuel and air mixed with each other by the gas mixer 91 passes through the throttle 92 in the first flow direction and is guided to the flow direction changing section 811. The first flow direction is a direction substantially parallel to arrow A11 shown in FIG. 2, and is the flow direction when the air-fuel mixture passes through the throttle 92.

As indicated by an arrow A12 shown in FIG. 2, the flow direction of the air-fuel mixture guided to the flow direction changing section 811 is changed from the first flow direction to the second flow direction in the flow direction changing section 811. In other words, the flow direction changing unit 811 changes the flow direction of the air-fuel mixture from the first flow direction when the air-fuel mixture passes through the throttle 92 to the second flow direction different from the first flow direction. In this embodiment, the second flow direction is a direction substantially parallel to the horizontal direction of the arrow A12 shown in FIG. 2, and in the example shown in FIG. 2, it is perpendicular to the first flow direction. Then, the air-fuel mixture whose flow direction has been changed from the first flow direction to the second flow direction by the flow direction changing section 811 is guided to the collecting section 812 .

As indicated by the arrow A13 in FIG. 2, the air-fuel mixture guided to the gathering portion 812 is first guided along the second flow direction (that is, the horizontal direction of the arrow A13). Thereafter, the air-fuel mixture is guided to a plurality of intake pipes 82. That is, the collecting section 812 guides the air-fuel mixture guided from the flow direction changing section 811 along the second flow direction, and then guides it to the plurality of intake pipes 82 .

The air-fuel mixture guided to the plurality of intake pipes 82 is distributed to a plurality of cylinders (four cylinders in this embodiment) of the engine 2. In other words, the plurality of intake pipes 82 distribute the air-fuel mixture led from the intake main body 81 to a plurality of cylinders (four cylinders in this embodiment) of the engine 2.

Specifically, the air-fuel mixture guided to the first intake pipe 821 is passed through a first intake port (not shown) formed in the cylinder head 4 to the first cylinder (not shown) formed in the cylinder block 3. (not shown). The air-fuel mixture guided to the second intake pipe 822 is supplied to a second cylinder (not shown) formed in the cylinder block 3 via a second intake port (not shown) formed in the cylinder head 4. be done. The air-fuel mixture guided to the third intake pipe 823 is supplied to a third cylinder (not shown) formed in the cylinder block 3 via a third intake port (not shown) formed in the cylinder head 4. be done. The air-fuel mixture guided to the fourth intake pipe 824 is supplied to a fourth cylinder (not shown) formed in the cylinder block 3 via a fourth intake port (not shown) formed in the cylinder head 4. be done.

Here, depending on the engine, the flow direction of the air-fuel mixture when it passes through the throttle may be parallel to the flow direction of the air-fuel mixture when it flows through the intake body. For example, the engine 2A according to the comparative example shown in FIG. 3 includes an intake manifold 8A, a gas mixer 91, and a throttle 92. The intake main body 81A of the intake manifold 8A has a gathering portion 812, but does not have a flow direction changing portion 811 as shown in FIG. 2, for example. In the engine 2A according to the comparative example shown in FIG. 3, the flow direction of the air-fuel mixture when it passes through the throttle 92 is parallel to the flow direction when the air-fuel mixture flows through the intake body 81A. That is, the flow direction of the air-fuel mixture when it passes through the throttle 92 is parallel to the arrow A21 shown in FIG. The flow direction when the air-fuel mixture flows through the intake main body 81A is a direction parallel to the horizontal direction of the arrow A22 shown in FIG. In this way, in the engine 2A according to the comparative example shown in FIG. 3, the air-fuel mixture supplied from the gas mixer 91 passes through the throttle 92 and flows through the intake body 81A along the axis of the gas mixer 91 without changing the flow direction. flows. Then, the air-fuel mixture that has flowed through the intake main body 81A is distributed to a plurality of cylinders of the engine 2A by a plurality of intake pipes 82. In this case, variations in air-fuel ratio among the plurality of cylinders of the engine 2A may be relatively large.

On the other hand, according to the engine 2 and the intake manifold 8 according to the present embodiment, the flow direction changing unit 811 receives the air-fuel mixture that has passed through the throttle 92, and changes the flow direction of the air-fuel mixture from the first flow direction to the first flow direction. 2 Change to flow direction. The first flow direction is the flow direction when the air-fuel mixture passes through the throttle 92. The second flow direction is a flow direction different from the first flow direction, and in the example represented in FIG. 2 is perpendicular to the first flow direction. Then, the collecting section 812 guides the air-fuel mixture guided from the flow direction changing section 811 along the second flow direction, and then guides it to the plurality of intake pipes 82 .

In this way, the air-fuel mixture that has passed through the throttle 92 has its flow direction changed from the first flow direction to the second flow direction in the flow direction changing section 811, and is then changed to the changed flow direction (i.e., the second flow direction). It flows along the gathering part 812. Therefore, the degree of mixing of fuel and air in the air-fuel mixture that has passed through the throttle 92 is improved in the flow direction changing section 811. Then, after the air-fuel mixture with improved mixing degree flows through the gathering portion 812 along the second flow direction, it is guided to the plurality of intake pipes 82. This makes it possible to suppress variations in air-fuel ratio among the plurality of cylinders of the engine 2.

Further, since the degree of mixing of the air-fuel mixture can be improved and variations in air-fuel ratio among the plurality of cylinders of the engine 2 can be suppressed, the volume of the gathering portion 812 can be reduced. That is, even without ensuring a relatively large volume as the volume of the gathering portion 812, it is possible to improve the mixing degree of the air-fuel mixture in the flow direction changing portion 811 and suppress variations in the air-fuel ratio among the plurality of cylinders of the engine 2. . Thereby, the intake manifold can be made smaller.

Further, according to the intake manifold 8 according to the present embodiment, the air-fuel mixture that has passed through the throttle 92 changes its flow direction from the first flow direction to the second flow direction perpendicular to the first flow direction in the flow direction changing section 811. be changed to. As a result, the degree of mixing of fuel and air in the air-fuel mixture that has passed through the throttle 92 is further improved in the flow direction changing portion 811.

Further, when the engine 2 is an internal combustion engine that operates on gaseous fuel, that is, a gas engine, the mixture passing through the throttle 92 is a mixture of gaseous fuel and air mixed with each other by the gas mixer 91. Therefore, the air-fuel mixture supplied from the gas mixer 91 passes through the throttle 92, and the flow direction is changed from the first flow direction to the second flow direction in the flow direction changing section 811, and the flow direction is changed (i.e., the flow direction is changed to the second flow direction). 2 flow direction) through the gathering portion 812. Therefore, the degree of mixing of the gaseous fuel and air in the air-fuel mixture that has passed through the throttle 92 is improved in the flow direction changing section 811. Then, after the air-fuel mixture with improved mixing degree flows through the gathering portion 812 along the second flow direction, it is guided to the plurality of intake pipes 82. This makes it possible to suppress variations in the air-fuel ratio among the plurality of cylinders of the engine 2, in other words, variations in the concentration of gaseous fuel between the plurality of cylinders in the engine 2.

Next, an example of the results of studies carried out by the present inventor will be explained with reference to the drawings.
FIG. 4 is a graph illustrating the relationship between each intake port of the engine and the equivalence ratio according to the present embodiment.
FIG. 5 is a graph illustrating the relationship between each intake port and the equivalence ratio of the engine according to the comparative example.

The inventor conducted a study to measure the equivalence ratio φ of each intake port in the engine 2 according to the present embodiment and the engine 2A according to the comparative example. The equivalence ratio φ represents the degree of mixing of fuel and air in the air-fuel mixture; in other words, it is an index representing the fuel concentration in the air-fuel mixture. The ratio of fuel to air (equivalence ratio φ) when the fuel is combusted in just the right amount is "1". That is, the equivalence ratio φ is expressed by the formula: "fuel-air ratio/stoichiometric fuel-air ratio". A mixture with an "equivalence ratio φ<1" is called a lean mixture. A mixture with an "equivalence ratio φ>1" is called a rich mixture.

The measurement results of the equivalence ratio φ of each intake port in the engine 2 according to the present embodiment are as shown in FIG. That is, the equivalence ratio φ at the first intake port P1 connected to the first intake pipe 821 (see FIGS. 1 and 2) is 1.01. The equivalence ratio φ at the second intake port P2 connected to the second intake pipe 822 (see FIGS. 1 and 2) is 1.02. The equivalence ratio φ at the third intake port P3 connected to the third intake pipe 823 (see FIGS. 1 and 2) is 1.02. The equivalence ratio φ at the fourth intake port P4 connected to the fourth intake pipe 824 (see FIGS. 1 and 2) is 1.03. The average value of the equivalence ratios φ at the first intake port P1, the second intake port P2, the third intake port P3, and the fourth intake port P4 is 1.02. As a result, the standard deviation of the equivalence ratio φ at the first intake port P1, the second intake port P2, the third intake port P3, and the fourth intake port P4 is 0.007.

On the other hand, the measurement results of the equivalence ratio φ of each intake port in the engine 2A according to the comparative example are as shown in FIG. That is, the equivalence ratio φ at the first intake port P1 connected to the first intake pipe 821 (see FIG. 3) is 1.06. The equivalence ratio φ at the second intake port P2 connected to the second intake pipe 822 (see FIG. 3) is 1.00. The equivalence ratio φ at the third intake port P3 connected to the third intake pipe 823 (see FIG. 3) is 1.01. The equivalence ratio φ at the fourth intake port P4 connected to the fourth intake pipe 824 (see FIG. 3) is 0.99. The average value of the equivalence ratio φ at the first intake port P1, the second intake port P2, the third intake port P3, and the fourth intake port P4 is 1.01. As a result, the standard deviation of the equivalence ratio φ at the first intake port P1, the second intake port P2, the third intake port P3, and the fourth intake port P4 is 0.027.

According to the results of this study, it can be seen that the variation in air-fuel ratio among the plurality of cylinders of the engine 2 according to the present embodiment is smaller than the variation in the air-fuel ratio between the plurality of cylinders in the engine 2A according to the comparative example. This shows that, compared to the engine 2A according to the comparative example, the engine 2 according to the present embodiment can suppress variations in the air-fuel ratio among the plurality of cylinders.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the scope of the claims. A part of the configuration of the above embodiment may be omitted or may be arbitrarily combined in a manner different from that described above.

2, 2A: Engine, 3: Cylinder block, 4: Cylinder head, 5: Head cover, 6: Oil pan, 8, 8A: Intake manifold, 31: Crank case, 81, 81A: Intake body, 82: Intake pipe, 91 : Gas mixer, 92: Throttle, 811: Direction changing part, 812: Gathering part, 821: First intake pipe, 822: Second intake pipe, 823: Third intake pipe, 824: Fourth intake pipe

Claims (2)

An intake manifold that guides a mixture of gaseous fuel and air mixed with each other by a gas mixer to a plurality of cylinders of an engine,
The engine is arranged such that its longitudinal direction is parallel to the arrangement direction of the plurality of cylinders in the side part of the engine, and the cylinders are arranged in the vertical direction, which is the vertical direction, of the directions orthogonal to the arrangement direction, which is the horizontal direction. an intake body that guides the air-fuel mixture that has passed through a throttle located directly below the gas mixer ;
a plurality of intake pipes connected to the intake main body and distributing the air-fuel mixture guided from the intake main body to the plurality of cylinders;
Equipped with
The intake main body is
A first air-fuel mixture is disposed directly below the throttle in the vertical direction, is connected to the gas mixer through the throttle at an upstream portion, receives the air-fuel mixture that has passed through the throttle, and is used when the air-fuel mixture passes through the throttle. a flow direction changing unit that changes the flow direction of the air-fuel mixture from the flow direction to a second flow direction perpendicular to the first flow direction;
disposed directly beside the flow direction changing section in a direction parallel to the arrangement direction and directly below the plurality of intake pipes in the up-down direction, connected to the flow direction changing section at an upstream portion and connected to the flow direction changing section at a downstream portion; a gathering part connected to the plurality of intake pipes and guiding the air-fuel mixture led from the flow direction changing part along the second flow direction and then to the plurality of intake pipes;
has
The first flow direction is downward in the up-down direction,
The second flow direction is a direction from the flow direction changing part toward the gathering part in a direction parallel to the arrangement direction,
The intake manifold, wherein the flow direction of the air-fuel mixture that is guided along the second flow direction and then guided to the plurality of intake pipes is upward in the vertical direction. a gas mixer that mixes gaseous fuel and air with each other to generate a mixture;
a throttle that allows the air-fuel mixture generated by the gas mixer to pass;
an intake manifold that guides the mixture that has passed through the throttle;
a plurality of cylinders that take inside the air-fuel mixture supplied from the intake manifold;
Equipped with
The intake manifold is
The gas mixer is arranged in a side part of the engine so that its longitudinal direction is parallel to the arrangement direction of the plurality of cylinders, and the gas mixer is arranged in the vertical direction, which is the vertical direction, among the directions perpendicular to the arrangement direction, which is the horizontal direction. an intake body that guides the air-fuel mixture that has passed through the throttle , which is located directly below the throttle;
a plurality of intake pipes connected to the intake main body and distributing the air-fuel mixture guided from the intake main body to the plurality of cylinders;
has
The intake main body is
A first air-fuel mixture is disposed directly below the throttle in the vertical direction, is connected to the gas mixer through the throttle at an upstream portion, receives the air-fuel mixture that has passed through the throttle, and is used when the air-fuel mixture passes through the throttle. a flow direction changing unit that changes the flow direction of the air-fuel mixture from the flow direction to a second flow direction perpendicular to the first flow direction;
disposed directly beside the flow direction changing section in a direction parallel to the arrangement direction and directly below the plurality of intake pipes in the up-down direction, connected to the flow direction changing section at an upstream portion and connected to the flow direction changing section at a downstream portion; a gathering part connected to the plurality of intake pipes and guiding the air-fuel mixture led from the flow direction changing part along the second flow direction and then to the plurality of intake pipes;
has
The first flow direction is downward in the up-down direction,
The second flow direction is a direction from the flow direction changing part toward the gathering part in a direction parallel to the arrangement direction,
The engine is characterized in that the flow direction of the air-fuel mixture that is guided along the second flow direction and then guided to the plurality of intake pipes is upward in the vertical direction.

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